Tsv substrate structure and the stacked assembly thereof

ABSTRACT

The disclosure provides a TSV substrate structure and the stacked assembly of a plurality of the substrate structures, the TSV substrate structure including: a substrate comprising a first surface, a corresponding second surface, and a TSV communicating the first surface with the second surface through the substrate; and a conductor unit completely filling the TSV, the conductor unit comprising a conductor body which has a first and a second ends corresponding to the first and second surfaces of the substrate, respectively.

CROSS REFERENCE TO RELATED PATENT APPLICATION

This application is a divisional application of co-pending U.S.application Ser. No. 12/969,250, filed Dec. 15, 2010, which claims thebenefit of Taiwan application Serial No. 099141056, filed on Nov. 26,2010, the contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a device of three-dimensionalintegrated circuit (3DIC), and more particularly, to a substratestructure with a through-silicon via (TSV) and the stacked assembly of aplurality of the substrate structures.

TECHNICAL BACKGROUND

The advantages of the three-dimensional-integrated-circuit (3DIC)technique, such as high performance, low power dissipation, low cost,compactness, integration of hetero-generous IC substrates, lead to apotential trend for developing the System on Chip (SoC). Wherein thethrough-silicon-via (TSV) technique plays a key role of being capable ofovercoming the limitations by the IC fabrication process and the lowdielectric-constant material, so that the interconnection among thestacked IC chips can be with lower cost and higher performance.

However, misalignment between the TSVs of the stacked IC substrates orconductor bumps between the stacked IC chips happened frequently in theassembly process of the 3DIC, which may lead to potential errors ordistortions in the communication of electrical signals. Furthermore, thereliability of the interconnection or assembly of the TSVs is subject tothe bumps, which tend to increase the resistance of TSV connection and,even more, to cause cracks or defects of opened circuit. Therefore, itis in need to develop a reliable structure of TSV substrates.

TECHNICAL SUMMARY

According to one aspect of the present disclosure, a first embodimentprovides a TSV substrate structure including: a substrate comprising afirst surface, a corresponding second surface, and a TSV communicatingthe first surface with the second surface through the substrate; and aconductor unit completely filling the TSV, the conductor unit comprisinga conductor body which has a first and a second ends corresponding tothe first and second surfaces of the substrate, respectively.

According to another aspect of the present disclosure, a secondembodiment provides a stacked assembly comprising a plurality ofsubstrate structures stacked on each other, each of the substratestructures including: a substrate comprising a first surface, acorresponding second surface, and a TSV communicating the first surfacewith the second surface through the substrate; and a conductor unitcompletely filling the TSV, the conductor unit comprising a conductorbody which has a first and a second ends corresponding to the first andsecond surfaces of the substrate, respectively.

Further scope of applicability of the present application will becomemore apparent from the detailed description given hereinafter. However,it should be understood that the detailed description and specificexamples, while indicating exemplary embodiments of the disclosure, aregiven by way of illustration only, since various changes andmodifications within the spirit and scope of the disclosure will becomeapparent to those skilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will become more fully understood from thedetailed description given herein below and the accompanying drawingswhich are given by way of illustration only, and thus are not limitativeof the present disclosure and wherein:

FIG. 1 is a perspective view of a TSV substrate structure according to afirst embodiment of the present disclosure.

FIGS. 2A and 2B are TSV substrate structures of theprotrusion_(top)-protrusion_(bottom) and recess_(top)-recess_(bottom)types, respectively, according to the first embodiment.

FIGS. 3A to 3C are architectures of the stacked assembly according tothe second embodiment of the present disclosure: example 1 to 3,respectively.

FIGS. 4A and 4B are architectures of the stacked assembly of example 4according to the second embodiment: with and without the insulator layeron the substrate surfaces, respectively.

FIGS. 5A and 5B are architectures of the stacked assembly of example 5according to the second embodiment: with and without the insulator layeron the substrate surfaces, respectively.

FIGS. 6A and 6B are architectures of the stacked assembly of example 6according to the second embodiment: with and without the insulator layeron the substrate surfaces, respectively.

FIGS. 7A and 7B are architectures of the stacked assembly of example 7according to the second embodiment: with and without the insulator layeron the substrate surfaces, respectively.

FIGS. 8A to 8M are the evolutional steps of fabricating the TSVsubstrate structure of FIG. 1.

DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

For further understanding and recognizing the fulfilled functions andstructural characteristics of the disclosure, several exemplaryembodiments cooperating with detailed description are presented as thefollowing. Hereinafter, for the description of the embodiments, in thecase of describing as forming each layer (film), portions, patterns orstructures “on” or “under” substrates, each layer (film), portions, orpatterns, “on” or “under” includes all of “directly” or “indirectly”formed things. In addition, a standard about “on” or “under” each layerwill be described based on the drawings. In the drawings, a thickness orsize of each layer is shown roughly, exaggeratedly, or briefly for sakeof convenience of description or for a definite description. Inaddition, a size of each element does not reflect entirely real size.

Please refer to FIG. 1, which is a perspective view of a TSV substratestructure according to a first embodiment of the present disclosure. InFIG. 1, the TSV substrate structure 100 comprises a substrate 110 havinga TSV 130 and a conductor unit 120 completely filling the TSV 130. Theconductor unit 120 is used as a channel of electrical and thermalinterconnection to build up a 3DIC.

The substrate 110 has a top and a bottom surfaces, or in terms of thefirst surface 111 and second surface 112 in this embodiment. Thesubstrate 110 includes at least one TSV 130, which communicates thefirst surface 111 with the second surface 112 through the substratebody. The TSV 130 itself has a column-shaped space to receive conductoror metal, so as to connect the two sides of the substrate 110electrically or thermally. For sake of simplicity, only one TSV isdepicted in the specification and drawings to illustrate the structureand fabrication of the embodiments; but is not limited thereby, whichcan be more than one TSV. Moreover, the TSV 130 or the conductor unit120 has a column body with a circular cross-section; but is not limitedthereby, which can be with a cross-section of rectangle, rhombus,polygon, or other shapes in accordance with the practical demand.

As shown in FIG. 1, an insulator layer 114 is formed on the side surfaceof the TSV 130 to electrically isolate the conductor unit 120 from thedevices or circuits in the substrate 110. In this embodiment, theinsulator layer 114 is also formed on the first and/or second surfaces111/112 of the substrate 110. The substrate 110 may be a die, a chip, awafer, an interposer connecting a die or a chip to a printed-circuitboard (PCB), or the combinations thereof, which are all applicable tothe embodiment.

The conductor unit 120, which completely fills the TSV 130 and has aconductor body 125 corresponding to the TSV 130, has a top and bottomterminals, or in terms of the first end 121 and second end 122,corresponding to the first and second surfaces 111/112 of the substrate,respectively. This embodiment is characterized partly by the solid andcomplete filling of the conductor body 125 in the TSV 130, so as toincrease conductivity and reliability of the conductor unit 120. Thisembodiment is also characterized by an extensional part 123 formed onthe side surface of the conductor body in proximity to the first or/andsecond ends of the conductor unit 120. As shown in FIG. 1, theextensional parts 123 of conductor are formed to surround the conductorbody 125 at both ends. The extensional part 123 is used to enhance thepositioning area of alignment when more than one TSV substratestructures 100 are stacked or assembled to form a 3DIC device. Theextensional part 123 is provided in this embodiment to increase thetolerance of aligning the TSVs between the TSV substrate structures 100and hence to diminish the parasitical devices or circuits due to themisalignment. The extensional part 123 may be formed at one or both endsof the conductor unit 120, or may not be formed at either end; thisdepends on the practical demand.

In order to facilitate alignment and assembly of the IC substrates withTSVs and to enhance the structural robustness of the assembly, theconductor unit 120 further comprises a recess 127 formed in the basesurface of the conductor body 125 at the first end 121 and a protrusion128 formed on the other base surface of the conductor body 125 at thesecond end 122, as the embodiment illustrated in FIG. 1. It should benoted that the recess 127 is not smaller than the protrusion 128 in areaand is not higher than the protrusion 128 in highness, to facilitate thealignment and assembly in the succeeding fabrication process of thestacked assembly of the TSV IC substrates. The conductor unit 120 iscomposed of copper in this embodiment, while it can be composed of theother metal or conductor material. Furthermore, the conductor unit 120has a cross-section of circle in the embodiment, while it can be with across-section of rectangle, rhombus, polygon, or other shapescorresponding to the TSV 130.

The formation of the protrusion on or the recess in the base surfaces ofthe two ends the conductor unit 120 may be in the other type. Forexample, a recess may be formed in the bottom surface of the conductorbody while a protrusion formed on the top surface of the conductor body.Further, two protrusions may be formed respectively on both basesurfaces of the conductor body as shown in FIG. 2A; or two recesses maybe formed respectively in both base surfaces of the conductor body asshown in FIG. 2B. The IC substrates with one of the two forgoing typesof conductor units in the TSV 130 can be assembled correspondingly. Thiswill be described in detail in the succeeding embodiments. Theprotrusion or recess may be formed at one or both ends of the conductorunit 120, or may not be formed at either end; this depends on thepractical demand.

To construct a 3DIC device, IC substrates of various potential types ofconductor units in the TSV in the first embodiment may be stacked oneach other or on a carrier. In a second embodiment according thispresent disclosure, a stacked assembly comprises: a first TSV substratestructure formed of one of possible types of conductor units in the TSVaccording to the first embodiment, a second TSV substrate structureformed of one of possible types of conductor units in the TSV accordingto the first embodiment, wherein the second TSV substrate structure isstacked on the first TSV substrate structure. Preferably, the TSV in thefirst TSV substrate structure corresponds to the TSV in the second TSVsubstrate structure.

Please refer to FIGS. 3A to 3C, which illustrate three examples of thestacked assembly according to the second embodiment. Example 1 providesthe stacked assembly of the TSV substrate structures of therecess_(top)-protrusion_(bottom) type as schematically shown in FIG. 3A,where a recess is formed in the top surface of the conductor body whilea protrusion formed on the bottom surface of the conductor body in eachTSV substrate structure. Example 2 describes the stacked assembly of theTSV substrate structures of the protrusion_(top)-recess_(bottom) type asschematically shown in FIG. 3B, where a protrusion is formed on the topsurface of the conductor body while a recess formed in the bottomsurface of the conductor body in each TSV substrate structure. On thecontrary, example 3 describes the stacked assembly of the TSV substratestructures of the recess_(top)-recess_(bottom) andprotrusion_(top)-protrusion_(bottom) types as schematically shown inFIG. 3C, where the recess_(top)-recess_(bottom) type means that tworecesses are formed respectively in both base surfaces of the conductorbody, while the protrusion_(top)-protrusion_(bottom) type is that twoprotrusions are formed respectively on both base surfaces. It should benoted in the neighboring TSV IC substrates that the recess is notsmaller than the corresponding protrusion in area and is not higher thanthe corresponding protrusion in highness, to facilitate the alignmentand assembly of the TSV IC substrates. The assembly may be proceeded asthe following: providing TSV substrate structures with correspondingrecesses and/or protrusions; aligning the TSVs and corresponding theconductor unit of the TSV substrate structures, and stacking one TSVsubstrate structure on the another one; and pressing the stacked TSVsubstrate structures vertically to the substrate surfaces. Since therecess is not smaller than the corresponding protrusion in area and isnot higher than the corresponding protrusion in highness, the pressureon the stacked TSV substrate structures can deform the conductor ofmetal or the like to fix the recess and protrusion tightly andcoincidently at the connection point, so as to increase conductivity andreliability of the TSV interconnection.

Based on the TSV substrate structures of therecess_(top)-protrusion_(bottom) type, several more exemplaryembodiments of various TSV substrate structures are provided below.Example 4 provides the stacked assembly of the TSV substrate structuresas schematically shown in FIGS. 4A and 4B, where each TSV substratestructure have a conductor unit with an extensional part surrounding theconductor body only in proximity to the bottom; FIG. 4A illustrates eachsubstrate with insulator layers on the side surface of the TSV and onthe top and bottom surfaces of the substrate, while FIG. 4B illustrateseach substrate with insulator layers only on the side surface of theTSV. Example 5 provides the stacked assembly of the TSV substratestructures as schematically shown in FIGS. 5A and 5B, where each TSVsubstrate structure have a conductor unit with an extensional partsurrounding the conductor body only in proximity to the top; FIG. 5Aillustrates each substrate with insulator layers on the side surface ofthe TSV and on the top and bottom surfaces of the substrate, while FIG.5B illustrates each substrate with insulator layers only on the sidesurface of the TSV. Example 6 provides the stacked assembly of the TSVsubstrate structures as schematically shown in FIGS. 6A and 6B, whereeach TSV substrate structure does not have any extensional part at thetop or bottom; FIG. 6A illustrates each substrate with insulator layerson the side surface of the TSV and on the top and bottom surfaces of thesubstrate, while FIG. 6B illustrates each substrate with insulatorlayers only on the side surface of the TSV.

Example 7 provides the stacked assembly of the TSV substrate structuresas schematically shown in FIGS. 7A and 7B, where each TSV substratestructure does not have any extensional part at either the top orbottom, each TSV substrate structure has a protrusion formed on thebottom surface of the conductor unit, and the insulator layer furtherincludes a recessed portion formed on the base surface of the conductorbody at the top end, wherein the area of the recessed portion is notlarger than the cross-sectional area of the conductor body and is largerthan the protrusion at the bottom; FIG. 7A illustrates each substratewith insulator layers on the side surface of the TSV and on the top andbottom surfaces of the substrate, while FIG. 7B illustrates eachsubstrate with insulator layers only on the side surface of the TSV. Itshould be noted, the TSV substrate structures in the second embodimentor in the foregoing examples in FIGS. 3 to 7 are not required to be inone identical type, TSV substrate structures of various types can bestacked or assembled according to this present disclosure.

Here is an exemplary embodiment of the fabrication process to fabricatethe TSV substrate structure in the foregoing embodiments. Referring toFIGS. 8A to 8M, which schematically illustrate the evolutional steps offabricating the TSV substrate structure of FIG. 1, wherein the copper isused to be the conductor material as an example. At first, a substrate110 having a TSV filled with copper is provided with an insulator layer114 of oxide formed on both the substrate surfaces. The back or bottomsurface of the substrate 110 is then planarized or polished until theexposure of the copper, as shown in FIG. 8A. Next, a barrier layer 401and a seed layer 402 are electroplated on the top surface of thesubstrate 110, as shown in FIG. 8B, where the barrier layer 401 and seedlayer 402 are conductor themselves. To form the extensional part of theconductor unit 120, the photolithography is used to pattern aphotoresist layer 403 on the seed layer 402, as shown in FIG. 8C. Acopper film 404 is electroplated on the seed layer 402 as shown in FIG.8D, where the copper film 404 cannot be deposited on the photoresist 403by electroplating. Next, the photoresist layer 403 is removed, and thesubstrate 110 is planarized or polished by the CMP (chemical mechanicalplanarization) method until the insulator layer 114 of oxide, as shownin FIG. 8E. A carrier 405 is then adhered onto the top surface of thesubstrate 110 with an adhesive layer 406 formed between the carrier 405and the substrate 110, as shown in FIG. 8F. Then another oxide layer isformed on the back surface of the substrate 110, as shown in FIG. 8G.Next, an appropriate pattern of photoresist layer 407 is selectivelyformed on the back surface of the substrate 110 by the photolithographyto etch the oxide layer 114, as shown in FIG. 8H. After that, thephotoresist 407 is removed, and the copper layer is then electroplatedon the back surface of the substrate 110, as shown in FIG. 81. Then abarrier layer 408 and a seed layer 409 are electroplated on the backsurface of the substrate 110, as shown in FIG. 8J. Next, thephotolithography is used to pattern a photoresist layer 410 on the backsurface of the substrate 110, and copper is then electroplated, as shownin FIG. 8K. The photoresist 410 is then removed, and the exposed barrierlayer 408 and seed layer 409 are then removed, too, as shown in FIG. 8L.Finally, the carrier 405 is removed, as shown in FIG. 8M, to completethe TSV substrate structure 100 as in FIG. 1. Also, the foregoingfabrication process may be used to fabricate other types of the TSVsubstrate structures according to the embodiments of this presentdisclosure, and is not limited to this exemplary TSV substrate structureof the recess_(top)-protrusion_(bottom) type.

With respect to the above description then, it is to be realized thatthe optimum dimensional relationships for the parts of the disclosure,to include variations in size, materials, shape, form, function andmanner of operation, assembly and use, are deemed readily apparent andobvious to one skilled in the art, and all equivalent relationships tothose illustrated in the drawings and described in the specification areintended to be encompassed by the present disclosure.

What is claimed is:
 1. A substrate structure comprising: a substratecomprising a first surface, a corresponding second surface, and athrough-silicon via (TSV) communicating the first surface with thesecond surface through the substrate; and a conductor unit completelyfilling the TSV, the conductor unit comprising a conductor body whichhas a side surface, a first endface corresponding to the first surfaceof the substrate, and a second endface corresponding to the secondsurface of the substrate.
 2. The substrate structure of claim 1, whereinthe conductor unit further comprises a first extensional part formed onthe side surface of the conductor body in proximity to the firstendface.
 3. The substrate structure of claim 2, wherein the firstextensional part surrounds the conductor body.
 4. The substratestructure of claim 2, wherein the conductor unit further comprises asecond extensional part formed on the side surface of the conductor bodyin proximity to the second endface.
 5. The substrate structure of claim4, wherein the second extensional part surrounds the conductor body. 6.(canceled)
 7. The substrate structure of claim 1, wherein the conductorunit further comprises: a first protrusion formed on the base surface ofthe conductor body at the first endface; and a second protrusion formedon the second endface of the conductor body.
 8. The substrate structureof claim 1, wherein the conductor further comprises: a first protrusionformed on the base surface of the conductor body at the first endface;and a recess formed in the second endface of the conductor body, whereinthe recess is not smaller than the first protrusion in area and is nothigher than the first protrusion in highness.
 9. (canceled)
 10. Thesubstrate structure of claim 1, wherein the conductor unit furthercomprises: a first recess formed on the base surface of the conductorbody at the first endface; and a second recess formed in the secondendface of the conductor body.
 11. (canceled)
 12. (canceled) 13.(canceled)
 14. (canceled)
 15. (canceled)
 16. (canceled)
 17. (canceled)18. A stacked assembly comprising a plurality of substrate structuresstacked on each other, each of the substrate structures comprising: asubstrate comprising a first surface, a corresponding second surface,and a TSV communicating the first surface with the second surfacethrough the substrate; and a conductor unit completely filling the TSV,the conductor unit comprising a conductor body which has a first endfaceand a second endface corresponding to the first surface and secondsurface of the substrate respectively, and a first extensional partformed on the side surface of the conductor body in proximity to thefirst endface.
 19. The stacked assembly of claim 18, wherein the firstextensional part surrounds the conductor body.
 20. The stacked assemblyof claim 18, wherein the conductor unit further comprises a secondextensional part formed on the side surface of the conductor body inproximity to the second end endface.
 21. The stacked assembly of claim20, wherein the second extensional part surrounds the conductor body.22. (canceled)
 23. The stacked assembly of claim 18, wherein theconductor unit further comprises: a first protrusion formed on a basesurface of the conductor body at the first endface; and a secondprotrusion formed on the base surface of the conductor body at thesecond endface.
 24. The stacked assembly of claim 18, wherein theconductor unit further comprises: a first protrusion formed on a basesurface of the conductor body at the first endface; and a recess formedin the base surface of the conductor body at the second endface, whereinthe recess is not smaller than the protrusion in area and is not higherthan the protrusion in highness.
 25. A stacked assembly comprising aplurality of substrate structures stacked on each other, each of thesubstrate structures comprising: a substrate comprising a first surface,a corresponding second surface and a TSV communicating the first surfacewith the second surface through the substrate; and a conductor unitcompletely filling the TSV, the conductor unit comprising a conductorbody which has a first endface and a second endface corresponding to thefirst surface and second surface of the substrate respectively, and afirst recess formed in the base surface of the conductor body at thefirst endface.
 26. The stacked assembly of claim 25, wherein theconductor unit further comprises: a second recess formed in the basesurface of the conductor body at the second endface.
 27. (canceled) 28.(canceled)
 29. (canceled)
 30. (canceled)
 31. (canceled)
 32. (canceled)33. (canceled)